🚀 go-pugleaf

Paul Andrew King <paul@nospam.demon.co.uk> wrote:

> In article <1daucda.1u09fgbxsd5cvN@p48.nas1.is2.u-net.net>,
> real-address-in-sig@flur.bltigibbet (Rebecca and Rowland) wrote:
> 
> >I see.  So all that MacOS X has lost compared to Rhapsody is the Blue
> >Box MacOS compatibility thingy.  Is that right?  And if so, how does the
> >slim-line new set of MacOS calls fit in with the general architecture?
> 
> The Blue box is - AFAIK - intended to stay for MacOs X.  How else will
> non-Carbon Mac programs run ? 

That, I didn't know (what I'd heard on the subject had confused me
greatly).  Having read some more stuff, it seems that what MacOS X will
have is this:

    Hardware
(PPC only; maybe
only 603 and above)
        |
 Kernel and stuff
  |            |
Carbon       Yellow box (Rhapsody/OpenStep API sort of thing)
  |
transparent
blue box

In other words, Carbon and Yellow Box are peers, sat directly on top of
the kernel (or whatever layer sits directly above the kernel), and the
blue box sits on top of Carbon, *but* the user has no indication of
this: it's transparent, and all applications (Carbon, blue box, and
yellow box) appear to be running on equal terms: no mucking about with
special blue box/yellow box windows.

I *guess* that the big difference is that when an old MacOS application
crashes, it only brings down the transparent blue box rather than the
whole machine (or there wouldn't be much point to the snazzy new
protected memory/pre-emptive multi-tasking scheme, would there?).  For
the same reason, I *guess* that the pre-emptive multi-tasking will apply
to the transparent blue box, so while applications running in it *think*
they're running in a co-operative multi-tasking environment, they're
actually only getting a certain fraction of `real' processor time, as
allowed to the blue box as a whole by the OS kernel's pre-emptive
multi-tasking mechanism.  Maybe.

> (A;though how long Apple will maintain it is
> anybody's guess).

I reckon Apple will maintain it for a very long time.  Why not?  All
Apple has to do is *maintain* it: no new development is needed, so the
job is relatively cheap.  Apple can hardly miss the point that *one*
reason people like Macs is that they last for ages and things `just
work'.  If Apple suddenly dropped blue box from the MacOS, an awful lot
of people would suddenly find that half their applications suddendly
stopped working when they upgraded the OS, which means lots of people
would decide that the best thing to do would be to *not* upgrade the OS,
thus reducing Apple's sales and hence income and profits.

Rowland.

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